Move _keyid.js from open-balena repo

_keyid.js

@@ -0,0 +1,79 @@
+'use strict';
+
+var crypto = require('crypto');
+var fs = require('fs');
+
+var base32 = (function() {
+  // Extracted from https://github.com/chrisumbel/thirty-two
+  // to avoid having to install packages for this script.
+  var charTable = "ABCDEFGHIJKLMNOPQRSTUVWXYZ234567";
+  var byteTable = [
+    0xff, 0xff, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f,
+    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+    0xff, 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06,
+    0x07, 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e,
+    0x0f, 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16,
+    0x17, 0x18, 0x19, 0xff, 0xff, 0xff, 0xff, 0xff,
+    0xff, 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06,
+    0x07, 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e,
+    0x0f, 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16,
+    0x17, 0x18, 0x19, 0xff, 0xff, 0xff, 0xff, 0xff
+  ];
+
+  function quintetCount(buff) {
+    var quintets = Math.floor(buff.length / 5);
+    return buff.length % 5 == 0 ? quintets: quintets + 1;
+  }
+
+  return function(plain) {
+    if (!Buffer.isBuffer(plain)) {
+      plain = new Buffer(plain);
+    }
+    var i = 0;
+    var j = 0;
+    var shiftIndex = 0;
+    var digit = 0;
+    var encoded = new Buffer(quintetCount(plain) * 8);
+
+    /* byte by byte isn't as pretty as quintet by quintet but tests a bit
+      faster. will have to revisit. */
+    while(i < plain.length) {
+      var current = plain[i];
+
+      if(shiftIndex > 3) {
+        digit = current & (0xff >> shiftIndex);
+        shiftIndex = (shiftIndex + 5) % 8;
+        digit = (digit << shiftIndex) | ((i + 1 < plain.length) ?
+          plain[i + 1] : 0) >> (8 - shiftIndex);
+        i++;
+      } else {
+        digit = (current >> (8 - (shiftIndex + 5))) & 0x1f;
+        shiftIndex = (shiftIndex + 5) % 8;
+        if(shiftIndex == 0) i++;
+      }
+
+      encoded[j] = charTable.charCodeAt(digit);
+      j++;
+    }
+
+    for (i = j; i < encoded.length; i++) {
+      encoded[i] = 0x3d; //'='.charCodeAt(0)
+    }
+    return encoded;
+  }
+})();
+
+function joseKeyId(der) {
+  var hasher = crypto.createHash('sha256');
+  hasher.update(der);
+  var b32 = base32(hasher.digest().slice(0, 30)).toString('ascii');
+  var chunks = [];
+  for (var i = 0; i < b32.length; i += 4) {
+    chunks.push(b32.substr(i, 4));
+  }
+  return chunks.join(':');
+}
+
+var derFilePath = process.argv[2];
+var der = fs.readFileSync(derFilePath);
+process.stdout.write(joseKeyId(der));